Table 3. The detailed survey questions.

Section/item	Description
Medical history (2 items)
1	Review the medical records regarding previous airway management before airway management
2	Obtain a medical history of co-morbidities that may affect the airway before airway management
Physical examination (1 item)
3	Perform comprehensive physical examination prior to airway management
Comprehensive scores (1 item)
4	Use an airway assessment tool (STOP-Bang questionnaire, El-Ganzouri score, and Wilson score, and in the ICU, the MACOCHA score) before airway management
Imaging (6 items)
5	Imaging of the airway may be considered in selected patients with anatomical abnormalities
6	Perform cervical X-ray before airway management in patients with suspected cervical trauma
7	Perform cervical X-ray before airway management in patients with congenital disorders (e.g., odontoid hyperplasia), degenerative conditions (e.g., cervical spondylosis, rheumatoid arthritis and ankylosing spondylitis) or syndromes such as Down’s, neurofibromatosis, osteogenesis imperfecta and Klippel-Feil)
8	Perform CT scan before airway management in patients with various congenital disorders, infectious pathologies, airway stenosis due to extrinsic or intrinsic tumours
9	Perform MRI to assess a patient’s airway before airway management
10	Perform ultrasound for airway assessment before airway management
Others (2 items)
9	Perform transnasal endoscopy to evaluate patients with periglottic lesions or abnormal airway structures before airway management
10	Perform virtual laryngoscopy and 3D printing for airway assessment

ICU, intensive care unit; CT, computed tomography; MRI, magnetic resonance imaging; 3D, three-dimensional.